IL41939A - Holder for pyrotechnical delay composition - Google Patents

Description

41939/ 3 HOLDER FOR A PYROTECHNICAL DELAY COMPOSITION mjjgyng ητιω.Ί nmsn nm ρ·»τπο 41939/2 The present invention relates to delay device for pyrotechnical uses, comprising a holder for a substantially gasless, combustible pyrotechnical delay composition constituted by a base part with a channellike recess in which the base part supports the composition and a covering part applied to the base part and covering the recess, the base part and/or the covering part then having at least one hole for connection of an ignition device for the composition and the same or the other part having a hole for connection with an utilization device which can be initiated by the composition.

These delay compositions are priaarily of the kind utilized for projectiles, bombs, rockets, etc. in which the composition, at a predetermined time after the firing, is to cause an initiation of some kind. In order to obtain little variation between different specimens of the type of ammunition in question, it is of essential importance that the delay composition works with great accuracy as regards the time.

The actual delay composition can consist of a composition which is known in itself which comprises an oxygen producer and an oxygen absorber. The composition burns at least substantially gaslessly and glowing.

The present invention gives an indication of a holder for a delay composition of this kind which permits the composition, with regard to the time aspect, to function with an accuracy which it has been impossible to attain with hitherto known devices. The property that constructea can mainly be considered to characterize a holder /according to the invention is that between the base part and the part covering said the cover ng part are app ied to eac ot er un er a pressure act ng upon the element and the composition, which causes the material in the element to yield, whereby the element adapts itself to the composition, regardless of the extent to which this fills up the recess.

As the composition in this way will be prestressed along its entire extent even if the composition is not uniformly distributed in the recess, and it will also be well enclosed, it can burn evenly and without expansion, which guarantees that the composition can function with the great accuracy desired, without any extremely severe requirements having to be placed on the correct extent of the filling of the composition in the recess. .

An embodiment presently proposed which has the characteristics significant for the invention will be described in more detail in the following, with reference to the attached drawings, in which figure 1 shows a vertical view and a cross-section of a delay Jaoide^-^ith-^sl^-eemo-si-Uuan, device, figure 2 shows a horizontal view and partly in cross- section a hairier according to figure 1 , figure 3 shows a vertical view and a cross-section of a first section (A-A) of the according to figure 2, and figure 4 shows a vertical view and a cross-section of a second section (B-B) of the ho tier according to figure 2.

In figure 1 , the reference designation 1 is a base part which has the form of an inner ring which has a substantially U-formed cross-section, the legs of the U-form then enclosing a channel-like recess, in which a delay composition 2 is applied. As the composition itself does not concern the actual invention, the composition will not be discussed in detail in the present application. Onto the "base part and covering said recess a covering part 3 is applied, which has the form of an outer ring, which also has a U-formed cross-secticn. This second ring is placed on top of the first -ring, and the legs in the respective U-forms then extend past each other.

Between the "base part 1 and the covering part 3, over said recess and composition 2, an element 4, of lead, which in the example of the embodiment is a ring-shaped washer, is applied. Said washer' is in contact with the base part, at the end surfaces of the legs of the U-form and at the composition. The washer is in contact with the covering part at the inner bottom surface of the U-form of this part. The base part and the covering part are applied to' each other under a pressure acting upon the element and therewith the composition, and is of such a magnitude that it causes the material in the element to yield, so that it adapts itself to the composition, regardless of the extent to which this fills up the recess. The filling can be uneven along the extent of the composition, which is illustrated in figure 1 , by a recess being formed in the washer in the left cross- section, while in the right cross-section a protrusion has been formed in the washer.

Said pressure is achieved by the outer sections 3a of the legs of the U-form in the inner ring, at the manufacture being folded over obliquel chamfered surfaces 1a of the inner ring. The material in the parts 1 and 3 can be chosen to conform to what is customary in this respect. As an alternative to having lead in the element 4, a material or an alloy can be chosen which has a viscous-elasticity at temperatures around room temperatures, and which does not participate in the combustion of the composition. a said device comprising Figure 2 illustrates more conspicuously the function of /the holder with the delay composition. The composition 2, which extends cylind- - rically, is provided with a stopping member 5, which achieves that a /¾evicetl§nthat can be initiated by the composition can be reached only from one combustion direction of the composition, counted from where an ignition device 7 is fastened. To an extent corresponding to the extent of the composition, the part 3 is provided with holes 8, spaced in a certain way and extending from the outside in towards the delay composition. The ignition device 7 can be placed arbitrarilly in any of the holes 8, each of which represents a specific delay time for which the composition is to act. After ignition has taken place at the device 7, the composition will thus burn in both the clockwise and the anti-clockwise directions, counted from the device 7. Owing - uti li zati on to the stopping member 5, however, the /device 6 will be actuated only from the clockwise direction.

Figure 3 shows an example of an ignition device 7, which supports a cup-formed part, in which is applied a friction ignition composition 9 and a flash composition 10. The latter composition is in contact with the delay composition 2 via a channel 11 , which is formed by both said holes in the first part and holes in the element 4. The friction ignition composition is initiated by a symbolically drawn striker pin 12, which via a spring 13 is applied to the friction ignition composition by an acceleration that takes place in the projectile or corresponding object in which it:.is assumed that the delay composition is applied. The striker pin can be included in devices of various kinds which are actuated by accelerations ; thus, these need not be described here. The friction ignition composition and the flash composition function in ways which are known in themselves. ut l izati on Figure 4 illustrates a/ device 6 which can be initiated by the delay composition 2, in the form of a powder pellet (flash type) applied in a hole for same in the first part 1. When the delay composition has ignited the powder pellet, this in turn usually sets off an initiating composition 15 of some kind, which is indicated symbolically with dash lines. The initiating composition can consist of black powder, and for example for illuminating ammunition can be utilized for separation of the shell, ignition of the flare etc.

The invention is not limited to the embodiment shown as an example, but can be subject to modifications within the scope of the following claims. Thus, the delay composition need not be circular.

Claims (4)

WHAT WE CLAIM IS: 41939/3

1. A delay device for pyrotechnical uses, comprising a holder for a substantially gasless, combustible pyrotechnical delay composition (2) constituted by a base part (1) defining channel-like recess which contains the composition (2) and a covering part (3) applied to the base part and covering the recess, the base part and/or the covering part then having at least one hole for the connection of an ignition device (7) for the composition and the same or the other part having a hole for connection with an utilization device (6) which can be initiated by the composition, characterised in that between the base part and the part covering said recesses an element (4) made of lead or other material with corres-ponding properties of plastic deformation is applied above the composition and in that the base part and the covering part are applied to each other under a pressure acting upon the element and the composition, which causes the material in the element to yield, whereby the element adapts itself to the composition, regardless of the extent to which this fills up the recess.

2. A device according to claim 1, in which the channellike recess has been given an enclosed extent, for example in the form of a circle, and is provided with a stopping member (5) which is intended to achieve that the said second mentioned hole is reached by the flame only from one burning direction of the composition, characterized in that the upper part along the extent of the recess has a number of holes (8) for the ignition device (7), each hole then representing a specific delay time for whi h he s n is 41939/2

3. A device according to claims 1 or 2, characterized in that the base part of the said holder is made in the form of an inner ring which has a cross-section which substantially a U-form and in which the legs in the U-form enclose the channel-like recess, that the element (4) is made as a ring-formed washer which together with the recess also covers said end surfaces of the U-legs, that the covering part has been given the form of an outer ring which has also a cross-section with a U-form, the outer ring then being placed on the inner ring and the element, the legs in the respective U-formed cross-sections then extending past each other.

4. A device according to claim 3, characterized in that the inner ring has obliquely chamfered surfaces at its lower parts of the U-form, and that the outer ring for achieving said pressure at the outer parts of the legs of its U-form are folded over said obliquely chamfered surfaces.